Where can I buy a S&P 500?

I'm interested in investing in the S&P 500, but I'm not sure where to start. Can you guide me on where I can purchase shares of the S&P 500? Are there any specific platforms or brokers that you recommend for beginners looking to get into the market? Additionally, are there any fees or minimum investments that I should be aware of when buying shares of the S&P 500? I'd appreciate any advice you can offer on navigating this process.